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<a name="Mnemonic-Attribute-1"></a>
<h4 class="subsection">17.19.7 Mnemonic Attribute</h4>
<a name="index-mnemonic-attribute"></a>

<p>The <code>mnemonic</code> attribute is a string type attribute holding the
instruction mnemonic for an insn alternative.  The attribute values
will automatically be generated by the machine description parser if
there is an attribute definition in the md file:
</p>
<div class="smallexample">
<pre class="smallexample">(define_attr &quot;mnemonic&quot; &quot;unknown&quot; (const_string &quot;unknown&quot;))
</pre></div>

<p>The default value can be freely chosen as long as it does not collide
with any of the instruction mnemonics.  This value will be used
whenever the machine description parser is not able to determine the
mnemonic string.  This might be the case for output templates
containing more than a single instruction as in
<code>&quot;mvcle\t%0,%1,0\;jo\t.-4&quot;</code>.
</p>
<p>The <code>mnemonic</code> attribute set is not generated automatically if the
instruction string is generated via C code.
</p>
<p>An existing <code>mnemonic</code> attribute set in an insn definition will not
be overriden by the md file parser.  That way it is possible to
manually set the instruction mnemonics for the cases where the md file
parser fails to determine it automatically.
</p>
<p>The <code>mnemonic</code> attribute is useful for dealing with instruction
specific properties in the pipeline description without defining
additional insn attributes.
</p>
<div class="smallexample">
<pre class="smallexample">(define_attr &quot;ooo_expanded&quot; &quot;&quot;
  (cond [(eq_attr &quot;mnemonic&quot; &quot;dlr,dsgr,d,dsgf,stam,dsgfr,dlgr&quot;)
         (const_int 1)]
        (const_int 0)))
</pre></div>




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